Kevin Federline Has Lost 25 Lbs. – and Counting

At least, that's what Kevin Federline is hoping as he whips himself back into shape after gaining enough weight to prompt some to label him with the unkind nickname.

"Kevin has lost 25 lbs., and is working on getting back into top shape," Federline's rep Marilyn Lopez tells PEOPLE.

Along with a new physique has come a renewed passion for getting back to work, Lopez says of the former back-up dancer. "He can't wait to start acting and dancing again and going on auditions next year."

Britney Spears's ex-husband – and father of her children – is also going strong in the romance department, according to a Federline friend.

"Kevin and Victoria are really doing great," says the friend, referring to his relationship with former college volleyball star Victoria Prince. "Although he and Britney don't talk much, they are co-parenting as best they can [and] working together to make the best decisions for their boys."

Earlier this week, Federline, 32, defended his ex-wife against allegations of sexual harassment by a security guard. His lawyer told PEOPLE Federline "is satisfied that the allegations are a product of economic motives."